Space-dyeing cellulose fibers by impregnating with mixture of diazonium

ABSTRACT

Process for the space-dyeing of yarn or sliver made from cellulose fibers, wherein a wound package of the said textile material is first impregnated with an aqueous liquor containing an alkaline substance and at least one component capable of entering into azo coupling, and subsequently - at least at one selected portion of the bobbin - one or several weakly acid aqueous solutions each containing a mixture of at least two diazonium compounds of aromatic amines having different diffusibility are injected into the goods so treated for development of the azo dyestuffs.

United States Patent [1 1 Von der Eltz et al.

[ 1 Jan. 22, 1974 SPACE-DYEING CELLULOSE FIBERS BY IMPREGNATING WITHMIXTURE OF DIAZONIUM Inventors: Hans-Ulrich Von der Eltz;

Doris-Jutta Fink, both of F rankfurt/Main, Germany Farbwerke HoechstAktiengesellschaft vormals Meister Lucius & Bruning, Frankfurt/Main,Germany Filed: Nov. 18, 1971 Appl. No.2 200,166

Assignee:

Foreign Application Priority Data Nov. 20, 1970 Germany 2057230 U.S. C18/14, 8/26, 8/46,

8/51, 8/54, 8/2 Int. Cl D06p 3/68 Field of Search 8/14, 26, 46

References Cited UNITED STATES PATENTS l/l967 Kramer et al 8/263,620,662 11/1971 Miyamoto 8/14 3,393,411 7/1968 McElveen 8/14 X3,120,422 2/1964 Weir 8/14 Primary ExaminerGeorge F. Lesmes AssistantExaminerPatricia C. Ives Attorney, Agent, or FirmI-Ienry W. Koster etal.

[57], ABSTRACT 1 Claim, No Drawings SPACE-DYEING CELLULOSE FIBERS BYIMPREGNATING WITH MIXTURE OF DIAZONIUM The present invention relates toa process for the space-dyeing of cellulose fibers.

From German Patent No. 1,244,104 it is known to dye yarn containingcellulose fibers with reactive dyestuffs irregularly in such a mannerthat no repetition of pattern occurs on the finished textile materialsafter the yarn thus dyed has been woven or knitted. According to thisdyeing method known as space-dyeing, an alkaline reactive dyestuffsolution is injected into the wound-up fibrous material at differentplaces and the wound package is then allowed to dwell until the dyestuffhas reacted with the cellulose.

When, alternatively, direct dyestuffs are used for the injectionsolution according to this process, as disclosed in Austrian Patent No.104,379, the yarn which has been space-dyed in this manner is notintended for.

use in certain textile articles since dyeings produced with thesedyestuffs show poor fastness to wet processing. Dyeings produced withreactive dyestuffs have substantially better fastness properties in thisrespect, but the use of this dyestuff class known according to the priorart from German Patent No. 1,244,104 implies a relatively complicatedprocess since prolonged dwelling times are required for the fixation ofthe dyestuffs on the fiber, thus reducing the production rate. Comparedto the use of substantive dyestuffs, the production of dyeings withreactive dyestuffs has the additional disadvantage of generallyinvolving substantially higher dyestuff costs.

Finally, according to the known methods for the space-dyeing of woundpackages by injection of dyestuff solutions, the number of shadesobtained in the bobbin depends on the number of injection locationschosen.

It has now been found that very fast multi-colored irregular dyeings canbe obtained on cellulose yarn or sliver by injection of dyeing liquorinto the wound-up fibrous material at least at one selected portion, ata favorable production rate and at reasonable dyestuff costs, especiallyfor deep shades, the number of shades obtained being superior to that ofinjection locations chosen, by first impregnating the wound package ofthe textile material with an aqueous liquor containing alkalinesubstances and components capable of entering into azo coupling, andthen injecting one or several weakly acid aqueous solutions containingmixtures of at least two diazonium compounds of aromatic amines having adifferent diffusing power, into the material thus treated for thedevelopment of the azo dyestuffs.

The coupling and diazo components used for the above-mentioned processas well as the coupling process itself are well known from the ice colortechnique. The development of azo dyestuffs on the fiber by the couplingof mixtures of several diazonium compounds with a single couplingcomponent has also been in use for a long time. It was, therefore,especially surprising when it appeared in the course of the process ofthe invention that some of the diazo components have such a differentdifiusing power on cellulose material that it is possible to obtain,around the injection location, a core consisting of a mixed color and aperipheral zone differing therefrom in its shade, upon injection of amixture of diazo components of such diffusibility into a bobbinpre-treated with a coupling component. Similar effects have not yet beenobtained upon dyeing from a long liquor in the dyeing apparatus as wouldcorrespond, on principle, to this injection method.

According to the process of the invention, pretreatment of the wound-upyarns with the impregnation baths containing the alkaline substances andthe coupling components is advantageously carried out in a dyeingapparatus, for example a device for dyeing cross-wound bobbins. Thisprocess step ensures simultaneous impregnation of a large number ofbobbins and thus does practically not reduce the production rate,especially since the second lot can be already impregnated while thebobbins of the first lot are injected with the solution of the diazocomponents. Moreover, the wound packages pre-treated with alkali andcoupling component can be stored and taken to use at any time and in anyamount since the impregnated bobbins, after drying, are stable uponstorage for an almost unlimited period of time if care is taken that anyaccess of moisture is prevented.

For the impregnation of the wound-up yarn, coupling components are used,preferably those of substantive nature toward the fibrous material.

These are compounds which couple in vicinal position to a hydroxy groupand do not have any solubilizing group, especially arylamides ofaromatic or heterocyclic o-hydroxycarboxylic acids or of acylaceticacids, as well as other aromatic or heterocyclic hydroxy compounds andcompounds containing an enolizable or enolized ketomethylene group in aheterocyclic ring. Such substances are, for example, the arylamides of2,3-hydroxy-naphthoic acid, 2-hydroxyanthracene-3- carboxylic acid,4-hydroxy-diphenyl-3-carboxylic acid,

2-hydroxy-carbazole-3-carboxylic acid, 3-hydroxydiphenylene-oxide-Z-carboxylic acid3-hydroxydiphenylenesulfide-2-carboxylic acid, aceto-acetic acid or ofbenzoylacetic acid. Furthermore, hydroxybenzenes, polyhydroxy-benzenes,hydroxynaphthalenes and pyrazo-lones have proved suitable among others,which may be substituted by non-ionic radicals.

As alkaline agents, any inorganic alkaline substance may be used in theimpregnation baths; preferably sodium hydroxide solution. These bathsmay also contain commercial-type non-ionic or anionic wetting agents fora better penetration of the yarn; for example wetting agents on thebasis of the reaction products of alkylene oxides with alkyl phenols, ofmixtures consisting of high-molecular oxyalkylation products of alkanolsor alkyl-phenols and alkyl-sulfuric acid esters of alkaneoralkyl-aryl-sulfonic acids, or of naphthalene-sulfonic acid derivatives.

The fibrous material is treated with the impregnation bath fo r 10 to 40minutes, preferably for 30 minutes, at a temperature of from 20 to50C,preferably at room temperature.

After impregnation, the bobbins are centrifuged or sucked and canimmediately be conducted to injection while still moist. Intermediatedrying of the pre-treated goods is not necessary but it results in ahigher liquor absorption during the subsequent injection since thefibrous material has a better absorptive power when dry.

As diazonium compounds for the development of the azo dyestuffs, anyprimary aromatic amine may be used, which yields water-insoluble mono-,disor polyazo dyestuffs with the above-specified coupling components,thus the tetrazonium compounds of aromatic diamines and the fast colorsalts obtainable by stabilization from the corresponding amines, too.The said suitable amines, among them amino-azo dyestuffs, have no ionicsubstituents.

To those skilled in the art it is a very easy and quick task todetermine the mixtures of diazo components suitable for the process ofthe invention. There is a great number of sample cards available fromthe dyestuff manufacturers for the choice of products of interestingshades. For testing the diazo components as to their diffusing power,aqueous solutions are prepared from the substances chosen, a mixture iscomposed from at least two of these solutions and a small amount of eachsolution is applied in a drop to a filter paper that has beenpreliminarily impregnated with the alkaline solution of a couplingcomponent and dried. In the case of mixtures having constituents ofdifferent diffusing power, this test demonstrates that a peripheral zonehaving a shade different from that of the center of the drop applied isobtained on the substrate. By'mixing more than two diazo componentshaving a different diffusing power, the variety of shades obtained cansubstantially be increased. Accordingly, in the case of combinations ofthree components, it is possible exactly to recognize by the shade ofthe inner spot and by the peripheral zone or zones having a differentcolor as well as by their breadth, whether or to what extent there is adifferent diffusing power of the individual constituents of the mixture.Starting from the center, the shade of these flow effects are graduallyturning into the pure color of the dyestuff which is obtained from thediazo component having the most rapid and far-reaching diffusing power.

According to the process of the invention, the acid solution of thediazonium compounds is injected under pressure into the package that hasbeen pre-treated with the coupling component, at least at one selectedportion of the wound material. The coloring liquid thus spreads outalong the limited injection zone, so that along the length of the yarnof the wound package, dyed and undyed areas of varying lengths areproduced at quite irregular intervals. The amount of the diazoniumcompounds injected may, of course, be varied. It depends on the desiredratio of dyed and undyed yarn. The injection of the dyeing liquor atseveral locations may be carried out separately or simultaneously. Toobtain a definite non-repeating pattern the injection positions must, ofcourse, be selected in a suitable manner. In order to produce amulti-color spotted yarn according to the invention, diazonium solutionsthat yield patterns of different shades upon development with thecoupling component may also be injected into the package, eitherseparately or simultaneously.

The injection mechanism contains as the most essential element a hollowinjection needle which has a perforated shaft (for more details seeAstrodyed (registered trademark) Technical Manual, Astro Dye Works,lnc., Calhoun, Ga. 3070l/USA, page 12, FIG. 14). The length of theneedle approximately corresponds to the thickness of the wound packageto be treated. The position of the injection needle support can berearranged so that the point of the injection needle can penetrate thepackage from the outside yarn layer to a desired position inside thethickness of the winding, whereupon the inflow of the dyeing liquor setsin. The flow of the liquor may be stopped again by a reversed motion ofthe needle support.

According to the novel process, generally weakly acid aqueous solutionsof the diazo components are injected into the wound-up fibrous material.The pH value of these solutions is adjusted to 4.5 6.9 by means of knownbuffer mixtures or weak acids, especially acetic acid. In some cases, itis suitable to add commercial-type non-ionic dispersants, for example onthe basis of the reaction products of alkylene oxides withcresol-camphor resins, or of mixtures consisting of oxyalkylated fattyalcohols and high-molecular-weight polyglycol ethers, to the injectionsolutions.

ln most cases, injection liquors of about room temperatures are used.

In this respect, it surprisingly appeard that the degree of diffusion ofthe individual components can be varied by a special selection of theacid or alkali-binder used in the diazonium salt solutions to beinjected.

Interesting fashionable effects can also be obtained by injecting, atone location of the bobbin, only a single diazo component which yields adeep blue shade, for example with the coupling component preliminarilyapplied, whereas solutions consisting of mixtures of diazo componentshaving a different diffusibility are used for the other injectionlocations.

After injection of the diazo components, the bobbins are allowed todwell for a short time, optionally for up to 5 minutes, and thenafter-treated as usual and dried. The dyeings produced according to theinvention show the good fastness properties typical of the ice colors.

In the textile articles dyed according to the process of the inventionthe cellulose fibers may be present in natural or regenerated form. Whathas been said for the dyeing of yarn is also true for the dyeing ofsliver.

The following Example serves to illustrate the invention.

EXAMPLE Six hundred and fifty Grams of wound-up cotton yarn were treatedat 20C for 30 minutes in a dyeing apparatus, at a goods-to-liquor ratioof l 25, with the impregnation bath hereinafter disclosed. The woundpackage was then sucked and dried. At different locations of the bobbin,the below-indicated injection solutions (1) and (2) were injected intothe ball of yarn thus impregnated, the liquor absorption of the fibrousmaterial being percent, calculated on the weight of the dry goods. Thetextile material dyed in this manner was then allowed to dwell for 5minutes and then aftertreated, in a dyeing apparatus, as usual anddried. lmpregnation bath 3.5 Grams of the compound of the formula weredissolved in 3.5 cc. of denatured ethyl alcohol, 3.5 cc. of sodiumhydroxide solution of 38Be and 7 cc. of hot water. 5 Grams of a wettingagent on the basis of mixtures consisting of high-molecular-weightoxyalkylation products of alkanols or alkyl-phenols and alkylsulfuricacid esters of alkaneor alkylaryl-sulfonic acids' were added to thesolution thus obtained, and the liquor was adjusted to l literbydiluting with water of 30C. Injection solution 1 This solution containeda mixture of two about equal amounts by weight of the followingsolutions 1 (a) and l (b): Solution 1 (a):

1 Liter of water contained 17 grams of the amine of the formula CzHs SOz-N ags which had been diazo tized by means of sodium nitrite andhydrochloric acid, the diazonium salt solution obtained having beenneutralized by adding sodium acetate,

3.5 cc. of acetic acid (of 50 percent strength) and 1 gram of adispersing agent on the basis of mixtures consisting of oxyalkylatedfatty alcohols and highmolecular-weight polyglyco] ethers. Solution 1(b):

1 Liter of water contained 72 g of the amino azo dyestuff of the formulawhich had been diazotized by means of sodium nitrite and hydrochloricacid,

20 cc. of acetic acid (of 50 percent strength) and l g of a dispersingagent as indicated sub solution 1 (a). Injection solution 2 Thissolution contained a mixture of two about equal amounts by weight of thefollowing solutions 2 (a) and 2 (b): Solution 2 (a):

1 Liter of water contained 13 g of the amine of the formula (I)CH;

NHz-HCI which had been diazotized by means of sodium nitrite andhydrochloric acid and the diazonium salt solution obtained had beenneutralized by means of sodium acetate,

1 g of a dispersing agent as indicated sub solution 1 4 cc. of aceticacid (of 50 percent strength) as well as a preliminary addition of 7 to10 g of sodium acetate. Solution 2 (b):

1 Liter of water contained g of the aminoazo dyestuff of the formulawhich had been diazotized by means of sodium nitrite and hydrochloricacid, and the diazonium compound obtained had been dissolved by pouringover a mixture of 500 cc. of luke-warm water, 5 cc. of a reactionproduct of alkylene oxides with cresol-camphor resins and 60 cc. ofacetic acid (of 50 percent strength). By adding cold water, thissolution was adjusted to 1,000 cc. and 10 g of sodium acetate and 10 to40 cc. of acetic acid (of 50 percent strength) were added.

A bobbin was obtained, the yarn of which showed, in the core of theinjection location, an intense brown red shade with mixed solution 1and, at the corresponding peripheral zone, a yellow shade in a reducedbreadth. The mixed solution 2 yielded, in the center of the injectionlocation, a medium brown shade and, in the quite large peripheral zone,a bright brilliant golden yellow shade.

Corresponding results to those of the preceding Example can be obtainedusing cellulose sliver for the dyeings instead of yarn.

What we claim is:

1. In a process for the space-dyeing of yarn or sliver made fromcellulose fibers by injection of dyeing liquid into the fibrous materialat least at one selected portion of the wound package, the improvementwhich comprises: first impregnating a bobbin of the said textilematerial with an aqueous liquor containing sodium hydroxide and at leastone coupler component capable of entering into azo coupling; andsubsequently injecting the so treated bobbin, for development of the azodyestuffs, with at least one weakly acid solution having a pH value inthe range of from 4.5 to 6.9, each of said solutions containing amixture of at least two diazonium compounds of aromatic amines havingdifferent diffusibility.

